Dithiothreitol is a reducing agent, so it helps to break bonds (like disulfide bonds) which will loosen the secondard structure of the RNA and facilitate RT enzyme initiation of transcription and processivity.

Dithiothreitol is a reducing agent, so it helps to break bonds (like disulfide bonds) which will loosen the secondard structure of the RNA and facilitate RT enzyme initiation of transcription and processivity.

Thank you for your reply. But normally there is no disulfide bond in the mRNAs, so i wonder.........

In low concentrations, DTT is used to stabilize proteins which possess free sulfhydryl groups. Thus, its addition to the RT mix would serve the purpose of protecting the enzymatic activity of the reverse transcriptase. I'm not sure if this is the reason by which DTT is added to RT, but is the only answer I can come up with. I've done thousands of RTs and never wonder why was I adding the DTT!

Science is a wonderful thing if one does not have to earn one's living at it(A.Einstein)